singleFrameDriver.py No locations for get ref_cat

The ref_cats directory should contain ps1_pv3_3pi_20170110, not actually be it. See the template path the butler’s expecting. So the tree should be something like:

/path/to/repo/
|-- various/
|-- directories/
|-- ref_cats/
    `-- ps1_pv3_3pi_20170110/
        |-- config.py
        |-- master_schema.fits
        |-- README.txt
        `-- <index>.fits